1. Technical Field
The present invention pertains to methods and apparatus for conducting fluid to and from the body of a living being. In a particular embodiment, the present invention is directed toward methods and apparatus for infusing of one or more liquids into a patient and/or conducting such fluid(s) from a patient. The present invention is further directed to methods and apparatus for transferring information via a conductive material in a common structure with fluid-conductive tubing.
2. Discussion of Prior Art
Generally, intravenous (“I.V.”) solutions or other liquids are infused into a patient by disposing a liquid-filled bag containing the intravenous solution or other liquid on a support structure, e.g., a pole, that permits either gravitational forces or the application of additional pressure to direct liquid from the bag through a preformed cylindrical tube into a patient.
Invariably, patients require infusion of one of more I.V. solutions during the course of their treatment. Accordingly, first responders and hospitals require that large amounts of tubing be stored in anticipation of treatment, thereby creating an issue of storage space adequacy. Hospitals and, more critically, ambulances have limited storage space for necessary medical supplies.
Similarly, storing I.V. tubing with its ends open and exposed to the ambient environment creates a contamination risk by unintentionally allowing micro-organisms, pyrogens, particulates, and other contaminants to enter and contact an inner surface of the intravenous tubing.
Furthermore, treatment may require that several tubes be connected to a patient at a single time. In addition to intravenous tubes, it may be necessary to connect other standalone lines to or near a patient, e.g., wire leads for warming the I.V. solution, conductive wiring for monitoring the patient's body functions, etc. The application of multiple standalone lines coupled with intravenous tubes to treat a patient can be confusing to a caregiver and may result in incorrect deployment and treatment. Moreover, manipulation of multiple lines can create a tangle and cause additional damage. Several organizational apparatuses attempt to manage multiple lines and tubes leading to a patient. These devices characteristically include a locking bar with several tube-receiving recesses that allow a caregiver to separate and label the independent lines and tubes. Such devices suffer from several drawbacks. As a first responder, a caregiver may not have the time to properly setup and/or label each line administered. Also, the devices are yet an additional item to manage and store during treatment.
As previously stated, infusion of intravenous fluids often relies on gravitational forces to infuse the contents of a liquid-filled bag into a patient. However, gravitational forces may be insufficient to drive certain viscous liquids, such as blood, into the patient at the necessary flow rate. There are several examples of prior art attempts to alleviate the aforementioned problem. For example, U.S. Pat. No. 4,090,514 (Hinck et al.) discloses a pressure infusion device including a bladder wherein the device encases a liquid-filled bag with the bladder surrounding at least eighty percent of that bag. Upon inflation of the bladder, liquid within the liquid-filled bag is infused under pressure into a patient. Further, U.S. Pat. No. 4,551,136 (Mandl) discloses a pressure infuser including an inflatable bladder that wraps about a bag. The bladder includes a vertical strip at each end and a strap that wraps about the bladder and bag. The vertical strips overlap to provide a complete wrap about the liquid-filled bag, while the strap maintains contact between the overlapping strip portions. The bladder is inflated to a desired pressure whereby pressure is applied by the bladder to the liquid-filled bad to infuse liquid into a patient.
Moreover, it is desirable during surgical procedures to maintain a patient's normal body temperature to avoid hypothermia and other complications brought about by the infusing liquids having temperatures below normal body temperature. Such complications include, but are not limited to, a decrease in patient body temperature, shock, cardiac dysfunction, increased coagulation time, and, in certain patients, an agglomeration of blood cells.
In order to avoid hypothermia and other complications as described above, warmers are typically employed during surgical and other medical procedures to maintain the infused liquid temperature at or near body temperature. Some examples include: U.S. Pat. No. 1,995,302 (“Goldstein”), utilizing a spirally wound electric resistance wire about the outer surface of an I.V. line; U.S. Pat. No. 3,247,851 (“Seibert”), disclosing a heating sleeve surrounding and extending along a length of tube to heat liquid as the liquid flows to a receptacle; and, U.S. Pat. No. 5,250,032 (“Carter, Jr. et al.”) teaching a housing having a channel for receiving a portion of an intravenous tube and a heating element mounted proximate a slot disposed within the channel to heat the tube.
The prior art warmer systems briefly described above suffer from several disadvantages. In particular, those systems tend to employ and control a single independent heating element disposed along a tube. This limits control accuracy of the liquid temperature, creating hotspots, i.e., sections of the tube being warmer than other sections of the tube, along the tube. Moreover, certain prior art warmer systems heat liquid flowing within an intravenous or other tube at a site located a substantial distance from the infusion location, thereby permitting heated liquid to cool by the time the heated liquid reaches the patient.